Downhole cutting tool and method

ABSTRACT

A downhole cutting tool includes a base including a first consolidated powder; and at least one cutting feature affixed to the base, the at least one cutting feature including a cutting material suspended in a second consolidated powder, wherein the base and the at least one cutting feature are both consolidated and bonded together simultaneously. Also included is a method of manufacturing a cutting tool.

BACKGROUND

Downhole cutting tools have a tendency to crack because they aremanufactured from very high strength (and therefore brittle) materials.Further, during manufacture, these tools are often subjected to veryhigh temperatures, such as to wet braze cutting material onto the tools,and extensive machining. These cracks limit the life of such tools,increasing material used, time spent replacing the tools, and overallcosts. Additionally, these tools need to be closely inspected for cracksand sometimes repaired even before use, further increasing cost, timeand materials. Improvements in downhole cutting tools are accordinglywell received by the industry.

BRIEF DESCRIPTION

A downhole cutting tool includes a base including a first consolidatedpowder; and at least one cutting feature affixed to the base, the atleast one cutting feature including a cutting material suspended in asecond consolidated powder, wherein the base and the at least onecutting feature are both consolidated and bonded togethersimultaneously.

A method of manufacturing a cutting tool includes layering a firstpowder and a second powder in a die, the second powder comprisingcutting material suspended therein; and simultaneously consolidating thefirst and second powders to form a base and at least one cuttingfeature, respectively, the simultaneous consolidating also bonding thebase to the at least one cutting feature.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions should not be considered limiting in any way.With reference to the accompanying drawings, like elements are numberedalike:

FIG. 1 is a cross-sectional view a cutting tool; and

FIG. 2 is a cross-sectional view of a mold for making the cutting toolof FIG. 1.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the disclosedapparatus and method are presented herein by way of exemplification andnot limitation with reference to the Figures.

Referring now to FIG. 1, a tool 10 is shown having a base 12 and aplurality of cutting features 14. A plurality of watercourses 16 isinterspaced with the plurality of cutting features 14, between adjacentones of the cutting features. The watercourses 16 are for enabling theflow of fluid to and from the cutting features 14, for example, to coolthe cutting features, wash away any cuttings, etc. The tool 10 isintended to be used downhole to cut or mill, for example, rock, earthenformations, cement, tubulars for fishing, downhole obstructions, etc.Opposite from the cutting features 14, the base 12 terminates in a neck18. The neck 18 is securable to a shoe casing or the like, via welds,threads, a friction fit, etc. Accordingly, the neck 18 may have an axiallength that significantly shorter than prior shoe heads or ends.

The base 12 (including the neck 18) and the cutting features 14 are bothformed from consolidated or compacted powder material or matrixes.Processes contemplated herein for consolidating powdered materialsinclude high velocity compaction and/or adiabatic processes, availableby Utron of Manassas, Va.; Hydropulsor of Karlskoga, Sweden; and LMC ofDeKalb, Ill. For example, in the high velocity or adiabatic process, apiston or ram is actuated at very high speed by igniting a gas such asargon. Other processes include field assisted sintering technology(FAST) or spark plasma sintering, in which an up to 300 ton force isapplied to powder in a die while pulses of electrical current are passedthrough the powder to create extremely high localized temperaturesbetween powdered particles. Another process is disclosed in U.S. Pat.No. 4,539,175, which patent is hereby incorporated by reference, inwhich a preform is first made by at least partially consolidating powderin a first die, moving the preform into a second die containing a bed ofheated ceramic particles, and then compressing the particles to solidifythe powder with a hydraulic ram or the like to full density or near fulldensity.

In any of these processes, the powder is first layered in a die and thensubjected to pressure, heat, etc. For example, a die 20 and a ram 22 isshown in FIG. 2 having powdered material or matrix 12′ and 14′ layeredtherein. The prime symbol is used to identify the powdered material ormatrix that form the elements having the corresponding numeral withoutthe prime symbol (e.g., the material 14′ forms the cutting features 14,the material 12′ forms the base 12 with the neck 18). Inserts 24 may beincluded for formation of the watercourses 16 in the base 12.

By layering the base material 12′ and the cutting feature material 14′in the die 20, simultaneous consolidation is possible. Additionally andalso simultaneously with the consolidation of the materials 12′ and 14′,the heat and/or pressure of the consolidation process bonds the cuttingfeatures 14 to the base 12. Advantageously, the need to perform aseparate bonding operation is avoided by layering the two materials inthe same die, saving time and manufacturing cost. Further, not having toperform a separate bonding operation avoids the cracking issues of priorsystems because additional machining to the tool, such as to formwatercourses, and the application of very high temperatures to the tool,such as to wet braze cutting material to the base of the tool attemperatures approaching 1900° F., can be avoided. Of course, one couldgrind or machine watercourses into the base 12 after consolidation, ifdesired, and this would still avoid the need for a separate bondingoperation.

Although heat and pressure is applied to the tool 10, this heat andpressure is applied only to the powdered materials or matrixes and isrequired to consolidate the powders 12′ and 14′. In fact, when inpowdered or matrix form, high temperatures can be desired for thecreation of high density parts. Importantly, the heat is applied onlyduring consolidation, not after the part is formed, such as prior casttools that tend to crack from subsequent applications of heat.Additionally, the increased strength obtainable by simultaneouslybonding and consolidating the components of the tool 10 avoids the needfor welded support members, which were previously used and resulted inprior tools being subjected to even more heat. As a result, crackingwill not readily occur according to the current invention, and instead,a single, bonded, and fully dense part is produced.

In one embodiment, the matrix 14′ that forms the cutting features 14comprises a polymeric or metallic composition of, for example, nickel,copper, iron, cobalt, or some other material exhibiting suitable bondingand strength qualities, having an embedded cutting material therein,which is one or more hard particulate materials such as tungstencarbide, cubic boron nitride, diamond, silicon carbide and combinationsincluding at least one of the foregoing and other similar materialsmixed therein before the matrix is cured. The mixture in one embodimentwill be homogenous while in other embodiments the cutting materialsmixed into the matrix may be concentrated in certain areas to affectmechanical properties (strength, wear resistance, wear pattern, etc.) ofthe cutting features 14 of the cutting tool 10. One embodiment utilizesa matrix material that is proprietary to and commercially available fromProtech Centerform Inc, Houston, Tex. In one embodiment, the basematerial 12′ is a powdered steel such that the base 12 can be welded orthreaded onto a shoe casing or the like.

While the invention has been described with reference to an exemplaryembodiment or embodiments, it will be understood by those skilled in theart that various changes may be made and equivalents may be substitutedfor elements thereof without departing from the scope of the invention.In addition, many modifications may be made to adapt a particularsituation or material to the teachings of the invention withoutdeparting from the essential scope thereof Therefore, it is intendedthat the invention not be limited to the particular embodiment disclosedas the best mode contemplated for carrying out this invention, but thatthe invention will include all embodiments falling within the scope ofthe claims. Also, in the drawings and the description, there have beendisclosed exemplary embodiments of the invention and, although specificterms may have been employed, they are unless otherwise stated used in ageneric and descriptive sense only and not for purposes of limitation,the scope of the invention therefore not being so limited. Moreover, theuse of the terms first, second, etc. do not denote any order orimportance, but rather the terms first, second, etc. are used todistinguish one element from another. Furthermore, the use of the termsa, an, etc. do not denote a limitation of quantity, but rather denotethe presence of at least one of the referenced item.

1. A downhole cutting tool comprising: a base including a firstconsolidated powder; and at least one cutting feature affixed to thebase, the at least one cutting feature including a cutting materialsuspended in a second consolidated powder, wherein the base and the atleast one cutting feature are both consolidated and bonded togethersimultaneously.
 2. The cutting tool of claim 1, wherein the firstconsolidated powder comprises steel.
 3. The cutting tool of claim 1,wherein the second consolidated powder comprises nickel, copper, iron,cobalt, or combinations including at least one of the foregoing.
 4. Thecutting tool of claim 1, wherein the cutting material comprises tungstencarbide, cubic boron nitride, diamond, silicon carbide, or combinationsincluding at least one of the foregoing.
 5. The cutting tool of claim 1,further including at least one watercourse proximate the at least onecutting feature.
 6. A method of manufacturing a cutting tool comprising:layering a first powder and a second powder in a die, the second powdercomprising cutting material suspended therein; and simultaneouslyconsolidating the first and second powders to form a base and at leastone cutting feature, respectively, the simultaneous consolidating alsobonding the base to the at least one cutting feature.
 7. The method ofclaim 6, wherein the first powder comprises steel.
 8. The method ofclaim 6, wherein the second powder comprises nickel, copper, iron,cobalt, or combinations including at least one of the foregoing.
 9. Themethod of claim 6, wherein the cutting material comprises tungstencarbide, cubic boron nitride, diamond, silicon carbide, or combinationsincluding at least one of the foregoing.
 10. A tool manufactured by theprocess of claim 6.